Golgi phosphoprotein 73 ( GP 73) has been regarded as a novel serum biomarker for the diagnosis of hepatocellular carcinoma ( HCC ) in recent years. It has been reported that the upregulation of GP 73 may promote the carcinogenesis and metastasis of HCC ; however, the mechanisms remain poorly understood. In this study, GP 73 correlates positively with matrix metalloproteinase‐2 ( MMP ‐2) in HCC ‐related cells and tissues. Further studies indicate that the knockdown of GP 73 blocks MMP ‐2 trafficking and secretion, resulting in cell invasion inhibition. Additionally, the knockdown of GP 73 induces the accumulation of intracellular MMP ‐2, which inhibits the phosphorylation of Src at Y416 and triggers the inhibition of SAPK / JNK and p53‐p21 signalling pathways through a negative feedback loop. Finally, the transactivation of MMP 2 was inhibited by the reduction in E2F1. This study reveals that GP 73 plays functional roles in the trafficking and equilibrium of epithelial‐mesenchymal transition ( EMT )‐related secretory proteins and that GP 73 serves as a new potential target for combating the metastasis of HCC .

With their properties of self-renewal and differentiation, embryonic stem (ES) cells hold great promises for regenerative therapy. However, teratoma formation and ethical concerns of ES cells may restrict their potential clinical applications. Currently, parthenogenetic embryonic stem (pES) cells have attracted the interest of researchers for its self-renewing and pluripotent differentiation while eliciting less ethic concerns. In this study, we established a model with ES and pES cells both stably transfected with a double-fusion reporter gene containing renilla luciferase (Rluc) and red fluorescent protein (RFP) to analyze the mechanisms of teratoma formation. Transgenic Vegfr2-luc mouse, which expresses firefly luciferase (Fluc) under the promoter of vascular endothelial growth factor receptor 2 (Vegfr2-luc), was used to trace the growth of new blood vessel recruited by transplanted cells. Bioluminescence imaging (BLI) of Rluc/Fluc provides an effective tool in estimating the growth and angiogenesis of teratoma in vivo. We found that the tumorigenesis and angiogenesis capacity of ES cells were higher than those of pES cells, in which VEGF/VEGFR2 signal pathway plays an important role. In conclusion, pES cells have the decreased potential of teratoma formation but meanwhile have similar differentiating capacity compared with ES cells. These data demonstrate that pES cells provide an alternative source for ES cells with the risk reduction of teratoma formation and without ethical controversy.

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